kramdown-mermaid

This is a gem for parsing Mermaid syntax, and is an extension of kramdown.

Currently, only parsing of Entity Relationship Diagrams is supported, but we hope to support parsing of Class Diagrams and Sequence Diagrams and more in the future.

Installation

Add this line to your application's Gemfile:

gem 'kramdown-mermaid'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install kramdown-mermaid

Usage

require 'kramdown'
require 'kramdown-mermaid'

text = <<EOS

# some title
ccc **ddd** eee

# Image
![Wikimedia](https://en.wikipedia.org/wiki/Wikimedia_Commons#/media/File:Commons-logo-en.svg "Wikimedia")

some comments

erDiagram %% some comment
    hoges {
        bigint id PK
        int price
        date start_on
        datetime created_at
        datetime updated_at
    }

    fugas {
        bigint id PK
        int price
        datetime created_at
        datetime updated_at
    }

hoges |o--o{  fugas: "some comment"** 
EOS

Kramdown::Document.new(text, input: 'KramdownMermaid').to_hash_ast

# => 
{:type=>:root,
:options=>{:encoding=>#<Encoding:UTF-8>, :location=>1, :options=>{}, :abbrev_defs=>{}, :abbrev_attr=>{}, :footnote_count=>0},
:children=>
[{:type=>:header,
:options=>{:level=>1, :raw_text=>"some title", :location=>1},
:children=>[{:type=>:text, :value=>"some title", :options=>{:location=>1}}]},
{:type=>:p,
:options=>{:location=>2},
:children=>
[{:type=>:text, :value=>"ccc ", :options=>{:location=>2}},
{:type=>:strong, :options=>{:location=>2}, :children=>[{:type=>:text, :value=>"ddd", :options=>{:location=>2}}]},
{:type=>:text, :value=>" eee", :options=>{:location=>2}}]},
{:type=>:blank, :value=>"\n"},
{:type=>:header, :options=>{:level=>1, :raw_text=>"Image", :location=>4}, :children=>[{:type=>:text, :value=>"Image", :options=>{:location=>4}}]},
{:type=>:p,
:options=>{:location=>5},
:children=>
[{:type=>:img,
:attr=>{"src"=>"https://en.wikipedia.org/wiki/Wikimedia_Commons#/media/File:Commons-logo-en.svg", "alt"=>"Wikimedia", "title"=>"Wikimedia"},
:options=>{:location=>5, :ial=>nil}}]},
{:type=>:blank, :value=>"\n"},
{:type=>:p, :options=>{:location=>7}, :children=>[{:type=>:text, :value=>"some comments", :options=>{:location=>7}}]},
{:type=>:blank, :value=>"\n"},
{:type=>:er_diagram, :value=>"erDiagram %% some comment \n", :options=>{:location=>10}},
{:type=>:p,
:options=>{:location=>10},
:children=>
[{:type=>:text,
:value=>"hoges { \n    bigint id PK\n    int price\n    date start_on\n    datetime created_at\n    datetime updated_at\n  }",
:options=>{:location=>10}}]},
{:type=>:entity,
:value=>"  \n  fugas {\n    bigint id PK\n    int price\n    datetime created_at\n    datetime updated_at\n  }",
:options=>
{:entity=>"fugas",
:attributes=>
[{:type=>"bigint", :name=>"id", :constraint=>"PK"},
{:type=>"int", :name=>"price", :constraint=>nil},
{:type=>"datetime", :name=>"created_at", :constraint=>nil},
{:type=>"datetime", :name=>"updated_at", :constraint=>nil}],
:location=>24}},
{:type=>:relation,
:value=>"\n\nhoges |o--o{  fugas: \"some comment\"\n",
:options=>{:left_entity=>"hoges", :left_relation=>"|o", :right_relation=>"o{", :right_entity=>"fugas", :location=>26}}]}

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec or bundle exec rspec on root to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

PRs and issues are always welcomed on GitHub at https://github.com/38tter/kramdown-mermaid. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Kramdown::Mermaid project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.